Scoring algorithm to predict survival after nephrectomy and immunotherapy in patients with metastatic renal cell carcinoma: a stratification tool for prospective clinical trials

Abstract

Background: The objective of this study was to develop an algorithm capable of stratifying the survival of patients with metastatic renal cell carcinoma (RCC) after nephrectomy and immunotherapy.

Methods: The medical records of 173 patients who underwent radical nephrectomy for metastatic RCC and received recombinant interleukin-2 (IL-2)-based immunotherapy between 1989 and 2000 were evaluated. Survival was the primary endpoint and was assessed based on clinical, surgical, and pathologic parameters. The clinical parameters included age, gender, performance status, existing hypertension, thyroid-stimulating hormone (TSH) levels, location of metastases, and presenting symptomatology. The surgical features included the requirement for blood transfusion or adrenalectomy. The pathologic factors involved tumor stage, tumor size, nuclear grade, lymph node status, and histologic subtype. Disease-specific survival was estimated using the Kaplan-Meier method. Univariate and multivariate Cox proportional hazards models were used to determine associations between clinical and pathologic features and survival.

Results: The median follow-up was 3.2 years (range, 0.2-9.3 years). Death due to RCC occurred in 123 patients (71%) at a median of 13 months (range, from 0.1 months to 8.4 years) after nephrectomy. Multivariate analysis revealed that the following features were associated with survival: lymph node status (P = 0.002), constitutional symptoms (P = 0.005), location of metastases (P < 0.001), sarcomatoid histology (P = 0.003), and TSH level (P = 0.038). A scoring system based on the features in the multivariate model was created to stratify patients into low-risk, intermediate-risk, and high-risk groups. Estimated survival rates at 1 years, 3 years, and 5 years were 92%, 61%, and 41%, respectively, for the low-risk group and 66%, 31%, and 19%, respectively, for the intermediate risk group. The high-risk group had 1% survival at 1 year and no survivors at 3 years.

Conclusions: In patients with metastatic RCC who were treated with nephrectomy and IL-2 immunotherapy, regional lymph node status, constitutional symptoms, location of metastases, sarcomatoid histology, and TSH levels were associated with survival. The authors present a scoring algorithm based on these features that can be used to predict survival in patients who present with metastatic RCC and to stratify such patients for prospective clinical trials.